Classified area near a man door?

[Schmoleskin]

Having trouble finding something... I know a boundary seal is required for a conduit leaving a CL1 DIV2 location, but what about a near a man door that leaves the CL1 DIV2 location, going outside? I have been told that the area outside a man door (10' radius?) is also considered to be CL1 DIV2 within this radius, but I cannot find a section that specifies this.

It is a manufactured building, so I looked in Art 545, nothing there. It is not a garage or other specific occupancy with its own section, it is a pump room for disposal of fracking water. The reason it is CL1, DIV2 is because the water coming back out of the well can contain oil. it is generally separated out before disposal, but could possibly have oil in it, thus the CL1 DIV2 classification.

For the light fixture outside this man door, we were told this light has to be rated for CL1 DIV2 because of its proximity to the door, which is what I cannot locate in the code. The light is rated CL1 DIV2 in any case.

Additionally, if the space around the door is still considered to be part of the CL1 DIV2 space, then we really are not leaving the classified area with the conduit that feeds the light. Does that mean it could cross the wall boundary without a seal? Or is the space outside the door considered non-classified (if the radius around the man door information was incorrect)? If the area outdoors near the door is non-classified, I will definitely seal the boundary.

The safest thing is to probably just seal the boundary and end all doubt, but I was hoping someone could help me locate that bit about the space near the door, if it exists.

 

[Jim1959]

API RP 500 6.2.3.5 indicates that the area outside the door does not need to be classified in the case of a CID2 interior.

 

[rbalex]

Having trouble finding something... I know a boundary seal is required for a conduit leaving a CL1 DIV2 location, but what about a near a man door that leaves the CL1 DIV2 location, going outside? I have been told that the area outside a man door (10' radius?) is also considered to be CL1 DIV2 within this radius, but I cannot find a section that specifies this.

It is a manufactured building, so I looked in Art 545, nothing there. It is not a garage or other specific occupancy with its own section, it is a pump room for disposal of fracking water. The reason it is CL1, DIV2 is because the water coming back out of the well can contain oil. it is generally separated out before disposal, but could possibly have oil in it, thus the CL1 DIV2 classification.

For the light fixture outside this man door, we were told this light has to be rated for CL1 DIV2 because of its proximity to the door, which is what I cannot locate in the code. The light is rated CL1 DIV2 in any case.

Additionally, if the space around the door is still considered to be part of the CL1 DIV2 space, then we really are not leaving the classified area with the conduit that feeds the light. Does that mean it could cross the wall boundary without a seal? Or is the space outside the door considered non-classified (if the radius around the man door information was incorrect)? If the area outdoors near the door is non-classified, I will definitely seal the boundary.

The safest thing is to probably just seal the boundary and end all doubt, but I was hoping someone could help me locate that bit about the space near the door, if it exists.

A few comments:

• Article 545 was irrelevant to start with. Only installations within the scopes of Articles 511 to 516 may be reasonably classified directly from the NEC. Other installations should be reviewed with Standards listed in NEC Section 500.4(B); especially Informational Note No.2. API RP 500 is one such Standard.
• With respect to API RP 500 Section 6.2.3.5, I would question the interior classification in the first place in light of NEC Section 500.5(B)(1)(1)

API RP 500 Section 6.2.3.5:
When a building (or similar enclosed area) is classified Division 2 “to the extent of the building” due to
specific oil or gas handling equipment enclosed by the building, it is not necessary to extend the Division 2 area
beyond the building due to non-vaportight walls or other openings (e.g. doors and windows) except when specific
equipment inside the building requires classification for distances beyond the openings. However, since these
openings occasionally may provide communication for flammable gases or vapors, for enhanced safety it generally is
recommended that non-explosion proof arcing or high temperature electrical equipment not be installed immediately
adjacent to such openings.

Section 500.5.(B)(1)(1):
In which ignitible concentrations of flammable gases,
flammable liquid-produced vapors, or combustible
liquid-produced vapors can exist under normal operating
conditions,...[Underline mine]

This means if it is possible for volatiles to appear under non-catastrophic failures the location is Class I, Division 1. NOTE: Normal does not necessarily mean common, usual or frequent conditions, only that it could happen. (Your statement: "...The reason it is CL1, DIV2 is because the water coming back out of the well can contain oil. it is generally separated out before disposal, but could possibly have oil in it, thus the CL1 DIV2 classification")
​

• API RP 500 Section 6.2.3.5 does not actually exclude the area around the door if it is correctly classified Division 2 either. If you read it carefully what would it be if there were no door in the first place. ("...except when specificequipment inside the building requires classification for distances beyond the openings")

​NOW - assuming everything is in fact classified Division 2 correctly - read the last sentence of NEC Section 501.15(B)(2) carefully.

As we usually do here, we recommend classification be done by someone qualified to do so AND who is familiar with the installation and processes involved.

 

[Schmoleskin]

Thanks for the great answers. These units go up to North Dakota, and I think as an AHJ, ND is pretty stringent. They may have just told the operators what they would have to build and what the classification had to be in order to pass their muster. It also might be our client, making sure they are covered. I should have been more clear about my comment that oil could be present, that is just the reason why I think they are classified this way. The bottom line for us is that they ordered a CL1 DIV2 pump room, and we did not get to comment on whether that is really required or not.

Since I posted the first question, I was able to determine that the request to consider the area around the door as hazardous came from our client, as above, and not from any NEC requirement. That said, I sealed at the boundary. Thanks again.

 

[rbalex]

Thanks for the great answers. These units go up to North Dakota, and I think as an AHJ, ND is pretty stringent. They may have just told the operators what they would have to build and what the classification had to be in order to pass their muster. It also might be our client, making sure they are covered. I should have been more clear about my comment that oil could be present, that is just the reason why I think they are classified this way. The bottom line for us is that they ordered a CL1 DIV2 pump room, and we did not get to comment on whether that is really required or not.

Since I posted the first question, I was able to determine that the request to consider the area around the door as hazardous came from our client, as above, and not from any NEC requirement. That said, I sealed at the boundary. Thanks again.

No problem. I will say in nearly 50 years of classifying locations, I've never seen a qualified local AHJ (even fire marshals). Of course, it doesn't mean they're not out there - I've just never seen it. I put much greater stock in the client's insurers and their own engineering staff or qualified consultants.

Since ND appears to be on the 2014 NEC, if the classification is correct, the boundary seal doesn't need to be explosionproof. (You did read the last sentence of NEC Section 501.15(B)(2) carefully - right )

 

[rbalex]

No problem. I will say in nearly 50 years of classifying locations, I've never seen a qualified local AHJ (even fire marshals). Of course, it doesn't mean they're not out there - I've just never seen it. I put much greater stock in the client's insurers and their own engineering staff or qualified consultants.

Since ND appears to be on the 2014 NEC, if the classification is correct, the boundary seal doesn't need to be explosionproof. (You did read the last sentence of NEC Section 501.15(B)(2) carefully - right )

I should correct myself. It should have read "... I've never seen a qualified local AHJ (even fire marshals) that can properly classify locations." The fact is, once a location is properly classified, most local AHJs do a fine job determining a proper installation. It's just they have an extremely strong tendency to over-classify on their own, "just to be safe."

 

[Schmoleskin]

Bob, I did read that last sentence, and saw that the required seal did not *have* to be explosion proof. However, since I personally have never seen a non-explosion proof sealing fitting, I am betting there's a high probability the ND inspector will not have seen one either. I just don't want our client out there answering questions like, "What in heck is that thing?" Besides, we have the regular ones in stock.

Now what's really funny, is that our client asks us to not fill all the sealing fittings here, and says that they'll fill them on-site after commissioning. We got a building back (someone else's) that had gotten burned up because lightning struck and ruptured the nearby slop oil tank (the stuff left over after the water is separated out). Gasp! The sealing fittings had never been filled, but I'll bet you saw that coming a mile away... TYVM

 

[petersonra]

When the companies I worked for had to install seals on equipment I had them hold back on the fill just in case we had to add something in the field. We put big red tags on them that could not easily be missed indicating they were not filled.

 

[csc_wyo]

API RP 500 6.2.3.5 indicates that the area outside the door does not need to be classified in the case of a CID2 interior.

"...except when specific equipment inside the building requires classification for distances beyond the openings.

It's very common for O&G skids to be designed under the philosophy "cram 10lbs of $#!% in a 5lb bag". I would wager that the inside of his produced water pump skids also have some or all of relief valves, pumps, sump pit, and strainers/filters which could easily extend this boundary on non vapor-tight walls.

Schmoleskin, where is your electrical equipment and controls located? Are these externally rack mounted at your sites or are they integral to your pump skid? If either of the above is integral to the skid, special considerations of the construction of the skid should be looked at to ensure you're meeting the intent of NEC and API RP 500.

 

[Schmoleskin]

The electrical equipment, an MCC, PLC, and the VFD for the main salt water disposal pump are on the skid, in an electrical room behind a boundary wall, considered non-classified. Conduits penetrate this wall, but are sealed off and caulked. There is other equipment outside that belongs to the water pipelines that enter the skid (pressure, flow, and temperature instruments, control valves, tank levels, etc.). We wire some PLC channels and power out to field interface junction boxes for this stuff. There are several configurations they have accounted for, a direct truck-in unloading site, a local tank of separated water, or an incoming water pipeline or two.

All the other processing and separation, that results in the saltwater that gets disposed of with these units, is done elsewhere. Not sure how far away this other process is, we just ship the finished pump skids out to the client. As I wrote earlier, the water that enters via the pipeline inlet is supposed to be free of combustibles, so I suppose the C1D2 classification in the pump room is either mandated by the State, or just considered to be best practice, or suchlike. You are correct, there is a sump, but I don’t think there is a filter in these, as there is no pair of pressure transmitters for delta-P. I might try to pick someone’s brain about all of this during our next FAT.

i am not familiar with API RP 500, just NEC, but am going to search a bit for some info, thanks.

"...except when specific equipment inside the building requires classification for distances beyond the openings.

It's very common for O&G skids to be designed under the philosophy "cram 10lbs of $#!% in a 5lb bag". I would wager that the inside of his produced water pump skids also have some or all of relief valves, pumps, sump pit, and strainers/filters which could easily extend this boundary on non vapor-tight walls.

Schmoleskin, where is your electrical equipment and controls located? Are these externally rack mounted at your sites or are they integral to your pump skid? If either of the above is integral to the skid, special considerations of the construction of the skid should be looked at to ensure you're meeting the intent of NEC and API RP 500.

 

[Strathead]

I should correct myself. It should have read "... I've never seen a qualified local AHJ (even fire marshals) that can properly classify locations." The fact is, once a location is properly classified, most local AHJs do a fine job determining a proper installation. It's just they have an extremely strong tendency to over-classify on their own, "just to be safe."

Hear, hear. For those who don't know, NFPA 497 deals with classification of gasses. And my experience is that most Engineers and Architects don't properly classify areas also. When you have a set of plans and you ask a question about the classified areas, crickets are the most likely response. Or you get the run around like as an electrician I should know how to classify the area. As time goes by, I find more and more things that have other codes driving them. Emergency egress lighting is a big one. Just the other day, I discovered that there is an NFPA code that deals with article 700 transfer switches and equipment. Specifically learned that an Emergency ATS can't be in the same room as normal power. Who knew. (except the geniuses here, of course.)